/* 基础重置与字体 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f8f9fa;
}

/* 页头样式 */
.site-header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-align: center;
    padding: 3rem 1rem;
    margin-bottom: 2rem;
}

.site-header h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
}

.site-header p {
    font-size: 1.1rem;
    opacity: 0.9;
}

/* 主容器 */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 紧急提醒区域 */
.deadline-alert {
    background: #fff3cd;
    border-left: 4px solid #ffc107;
    padding: 1rem;
    margin-bottom: 2rem;
    border-radius: 4px;
}

.deadline-alert h2 {
    color: #856404;
    margin-bottom: 0.5rem;
}

/* 作业列表表格 */
.homework-list {
    background: white;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    margin-bottom: 2rem;
}

.homework-list h2 {
    margin-bottom: 1rem;
    color: #495057;
}

table {
    width: 100%;
    border-collapse: collapse;
}

thead {
    background-color: #e9ecef;
}

th, td {
    padding: 12px 15px;
    text-align: left;
    border-bottom: 1px solid #dee2e6;
}

tr.urgent {
    background-color: #fff5f5;
}

tr.completed {
    opacity: 0.7;
}

/* 状态徽章 */
.status-badge {
    padding: 4px 8px;
    border-radius: 12px;
    font-size: 0.85rem;
    font-weight: bold;
}

.status-badge.doing {
    background-color: #fff3cd;
    color: #856404;
}

.status-badge.todo {
    background-color: #d1ecf1;
    color: #0c5460;
}

.status-badge.done {
    background-color: #d4edda;
    color: #155724;
}

/* 页脚 */
.site-footer {
    text-align: center;
    padding: 2rem;
    color: #6c757d;
    border-top: 1px solid #e9ecef;
}